Valve train assembly for internal combustion engines



J. CHADWELL March 25, 1958 VALVE TRAIN ASSEMBLY FOR INTERNAL COMBUSTIONENGINES Filed March 22, 1957 2 Sheets-Sheet 1 John Chadwel/ m m T m m 3,W 5 ..M# F n n March 25, 1958 J, CHADWELL 2,827,888

VALVE TRAIN ASSEMBLY FOR INTERNAL COMBUSTION ENGINES Filed Mm 22. 1957'2 Sheets-Sheet 2 //2 /48- y /34 Fig. 6

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United States Patent VALVE TRAIN ASSEMBLY FOR INTERNAL COMBUSTIONENGINES John Chadwell, Cincinnati, Ohio Application March 22, 1957,Serial N 0. 647,831

4 Claims. (Cl. 123-90) This invention relates in general to new anduseful improvements in internal combustion engines and more specificallyto an improved valve train assembly.

At the present time, the return springs for the valve. of internalcombustion engines are disposed concentric with the valve stems and areconnected directly to the valves for the purpose of urging the valves toclosed positions. However, the position of the springs is such that alarge amount of heat is transferred to the springs, thus causing rapiddeterioration of the springs with the result that the valves do notproperly seat at high speeds after the internal combustion engine hasbeen run for a period of time.

It is therefore the primary object of this invention to provide a valvetrain assembly for internal combustion engines wherein the return springfor the valve is positioned remote from the valve so as to eliminate theeffect of heat on the valve spring, the valve spring being disposed inengagement with the rocker arm for the particular valve so as to urgethe valve to a closed position through the rocker arm.

Another object of this invention is to provide an improved valve trainassembly for internal combustion engines wherein the rocker arm isprovided with a fitting which permits the positive connection, of avalve stem to the rocker arm and at the same time permits freedom ofrotation of the valve so as to prevent burning thereof and to insureproper seating of the valve.

Another object of this invention is to improve valve train assembly forinternal combustion engines, the valve train assembly including a rockerarm which is positively connected to a valve and which has engagedtherewith a spring whereby the rocker arm is positively urged towards avalve closing position by the spring and the valve is urged to such aclosed position by its positive connection with the rocker arm. a

Another advantage'of the present invention is that the "constructionthereof'is such that the rocker arms may be constructed to have agreater ratio in order to efiect a greater travel of the valve, thusincreasing the .valve opening and effectingbetter breathing of theinternal combustion engine.

'"Another'object of 'this invention is to provide an improved fittingfor positively connecting a valve stem to a rocker arm, the fittingincluding a ball member having a rodzextendiiig from one end thereof forattachment to the rocker arm and a socket fitting having a rodextending' from it in a 'direction generally opposite to thedirecprojects above the head 16.

of the overhead valve type and shows the valve train assembly which isthe subject of this invention;

Figure 2 is an enlarged, vertical, sectional view taken through thefitting connecting the rocker arm to the valve stem and shows thespecific details of construction of that fitting;

Figure 3 is an enlarged, sectional view taken substantially upon theplane indicated by the section line 33 of Figure 2 and shows further thedetails of construction of the socket member of the fitting;

Figure 4 is an enlarged, fragmentary, elevational view of one end of therocker arm and shows the details of the spring connection therewith;

Figure 5 is an enlarged, fragmentary, sectional view taken substantiallyupon the plane indicated by the section line 5--5 of Figure 4 and showsthe relationship of hold-down bolts for the spring;

- Figure 6 is a fragmentary, sectional view similar to Figure 1 andshows a modified form of the invention;

Figure 7 is an enlarged, fragmentary, sectional view showing theadjustable connection between therocker arm and the push rod; and

Figure 8 is an enlarged, fragmentary, sectional view showing theconnection between the spring retainer and the rocker arm.

Referring now to the drawings in detail, it will be seen that there isillustrated in Figure 1 a portion of an internal combustion engine whichis of the overhead valve type, the internal combustion engine beingreferred to in general by the reference numeral 10. The internalcombustion engine 10 includes a block 12 having a cylinder 14. Overlyingtheblock 12 is a head 16 which is provided in a combustion chamber 18 inalignment with the cylinder 14. Extending through the head 16 forselective communication with the combustion chamber 18 is a gas passage20 which may be used for the entrance of a fuel-air gas mixture into thecombustion chamber 18 or for exhaust gases. The flow of gases throughthe passage 20 is controlled by a valve 22 which includes a head 24 anda valve stem 26. The valve stem 26 is guidingly dis posed in a bore 28in'the upper part of thehead l6 and In order to effect the actuation ofthe valve 22, the block 12 is provided with a bore 30 which is alignedwith a bore 32 in the head 16. The bores 30 and 32 have freely passingtherethrou gh an elongated push rod 34 whose lower end is engaged with afollower (not shown) which is in turn engaged with a cam shaft (notshown) for vertical reciprocatory movement. It is to be noted that thepush rod 34 extends upwardly above the head 16 a considerable distance.

Carried by the head 16 and projecting thereabove is the valve trainassembly which is the subject of this invention, the valve trainassembly being referred to in general by reference numeral 36. The valvetrain assembly 36 includes a plurality of longitudinally spaced,upstanding rocker arm shaft supports 38, only one of the supports 38being illustrated. Extending longitudinal of the head 16 is a rocker armshaft 40 which is supported by the supports 33. Mounted on the rockerarm shaft 40 for rocking movement is a plurality of rocker arms 42. Itis to be understood that there is one rocker arm 42 and one push rod 34for each of the valves 22.

Carried by the underside of the rocker arm 42 at one end thereof is anadjustable fitting 44 for engagement with the upper end of the push rod34 so that the push rod 34 may urgethe rocker arm 42 to rock or rotatein a clockwise direction. The fitting 44 is adjustable so as to permitadjustment of the valve train as is necessary. It is to be understoodthat the fitting 44 may be of a conventional type. i Y i In order thatthe rocker arm 42 may control the position of the valve 22, :there isprovided a fitting which is referred to in general vby .the reference.numeral46. The

fitting 46 is carried at the opposite end of the rocker arm 42 from thefitting 44 and is connected to the underside thereof. Thefitting 46 isalso connectedto the upper end of the valve stem 26. The details =ofithefitting 46 will be set forth hereinafter.

In order that the valve 22 may be continuously urged towards a closedposition, there .is provided a spring assembly which is referred to ingeneral by the reference numeral 48. The spring assembly 48 includes a.cup shaped lower :bearing member .50, as is best illustrated in Figure4, which overliesthe one endof the rocker arm 42 generally in alignmentwith theifitting 44. Seated 1n theretainer $50.:isa heavydutycoillspring 52 of the general "type used :in conjunctionwith'valves'for returning of the valves to closed position. Overlyingthe upper end of the spring 52 ..is .aniinverted,tcupashaped retainer54. The spring :52 ;is retained .in a compressive state by "means "of aplate .56 'whichzoverlies :the retainer 54. I The plate 56 is positionedrelative :tosthe head 16 Ibyrneans of a plurality :of elongated bolts:58 whose lower ends .are

anchored in .thehead 16and whose upper ends are provided with nuts 60adjustablyxthreadedly engaged thereon. .By adjusting the nuts 60,thespring .52 may be adxzlosed position.

' Referring now to Figures 2 and Sin particular, it will be seen thatthere is illustrated the :details of the fitting 46. The fitting 46includes a .ball member 62 which .has secured thereto an elongated rod:64 whose opposite end is externally threaded as at 6.6.Ihe.1ighthand.end of the rocker arm 42, as viewediniFigure .1,.has thelower part thereof provided with an internally threaded bore 68 inwhichthe threaded portion '66 is threaded engaged. The rod 64 is retained inan' adjustedxposition relative to the rocker arm 42 by means of alockwasher 70 and a lock nut 72, the :lock nut 72 being engaged with thethreaded portion 66.

The fitting 46 also includes a socket member which is referred to ingeneral by the referencenumeral 74. The socket member 74 includes anupper half 76 and a lower half '78. The halves 76 and 78 are ofidentical construction with the exception that the upperhalf 76isprovided with an opening 80 .for the passage of the :rod 64 and there issecured to the lower half in alignment with the center of the opening 80an externally threaded :rod 82.

The rod 82 is:received in an internally threaded bore 84 in the upperend of the valve'stem 26.' .The rod 82 is locked in the bore 84 bymeansofallock washer .86'and a lock nut 88.

Inasmuch as the halves 76' and 78 are identical with the exceptions set{forth above, only the half 78 will be described in detail. The half 78includes a semi-spherical shell 90 which 'is provided with an annularconnecting flange 92. The connecting flange 92 of the halves 76 and 78are connected together byaflplurality of circumferentially spacedfasteners94.

Each of the halves 76.and 78 :also'includes a generally semi-sphericalball retainer 96 which is disposed within the confines of the shell 90and are concentric relative thereto. The ball retainer 96 is providedwith a plurality of openings 98 for'the passage of portionsof'aplurality of balls 100 which are disposed between the ball retainer 96and the shell 90. The balls 100 are so "disposed Where by they engagethe ballmember 62 so as toposition the socket member 74thereon. It is tobe noted that the ball retainer 96 is provided with a pluralityoifradiating sockets 102 which-are internally threaded and which havereceived therein fasteners 104 carried by the shell, 90. The fasteners104 serve to position the ball retainer '96 I 122 by means of 4.relative to the shell and also facilitate the assembly of halves 76 and78. 7

Although the rod 64 has been illustrated and described as beingconnected to the rocker arm 42 and the rod 82 has been illustrated anddescribed as connected to the valve stem 26, it is to be understood thatthe fitting 46 may be inverted from its position in Figure 2.

By placing the spring assembly 48 remote from the head 16, the hightemperatures-of the head 16 no longer affect the spring 52. This:assures a long life of the spring 52, as well as a constant springpressure on the valve 22. On the other hand, the detrimental featuresnormally resulting'from-the shifting of the valve spring are eliminatedby providing the fitting 46. The fitting 46 not only serves topositivelyactuate the valve 22, but also permits relative rotation between thevalve 22 and the rocker arm 42 even though the two are positivelyconnected together.

The particular arrangement of the components ofthe valve train assembly36 is such that the rocker arm 42 may extend further to the right, asviewed in Figure 1, than usual. By so increasing the length of oneend ofthe rocker arm '42, the ratio of the rocker arm 42 is changed,

and thus the valve 22 may be moved a greater distance fora like movementof the the opening of the valve 22, the valve push rod 34. Byincreasinga greater flow of gases past 22 is permitted, thus increasing theelficiency of the internal combustion engine 10.

The entire valve train assembly is covered by a rocker arm cover 106 ofthe usual typewhich is sealed with respect to the head 16 by means of agasket 108 to prevent leakage of oil which is used to lubricate thevalve train assembly. The cover 106 is retained in place by fasteners110.

Referring now to Figures 6, 7 and 8 in particular, it will be seen thatthere is illustrated a modified form of valve train which is referred toin general by the reference numeral 112. The valve train .112 is mountedon a head 114 which includes a plurality of valves, both intake andexhaust, only one of the valves 116 being illustrated. The valve 116includes a head 118 which is engaged with a seat 120 of the cylinderhead 114 land a stem 122 which is guidingly disposed in a bore 124formed in the upper part of the head 114.

For each of the valves 116, the head 114 is provided with a bore 126therethrou'gh through which there extends an elongated push rod 128. Thepush rod 128is reciprocatedin timed relation by a cam shaft (not shown)and serves to actuate .theassociated one of the valves116.

Mounted on the head .114 and extending upwardly therefrom'is a pluralityof -.longitu'dinally aligned .supports 130, only' one of which isillustrated. Suitably journaled in the supports 130 is a rocker shaftv132 .on which there is mounted for rocking movement :a plurality ofrocker arms 134. Only one rocker arm 134 is illustrated.

The rocker arm 134 is connected to the valve .stem a'fitting 136'whichis identical with the fitting 46.

In order that .the valve .116 may automatically be returned to a closedposition, .there isprovided a valve 'return spring 138.Thevalvereturnspring 138 extendsbetween the :rocker-arm- 134 and the.head 114. Secured to the upper surfaceofthehead .114 is :a' retainer140 for the lowerendof the valve :spring138. .A similar retainer 142 isconnected to the underside of'the rocker-arm :134

that the 'leftend of the rockerarm 134 is bifurcated to provide an upperflange 148 and a'ilower flange .150, the flanges 148'andJ150 beingdisposed in spaced, parallel relation. The flange 148 is provided withan internally threaded bore 152 which extends therethrough normal to theplane thereof and which has adjustably threaded therein a threaded shankportion 154 of a stop member 156. The threaded shank portion 154 isprovided with a lock nut 158 to retain the stop member in an adjustedposition.

The lower flange 150 is provided with a plug 160 which is removablythreadedly engaged therein and which is provided with a bore 162 alignedwith the internally threaded bore 152. Slidably disposed within the bore160 is a shank 164 of a follower 166 for the upper end of the push rod128. The follower 166 is provided with a spherical head 168 on the lowerend of the shank 164, the head 168 being seated in a socket 170 formedin the upper end of the push rod 128.

In order that the spherical head 168 may be retained in the socket 170at all times, there is provided a spring 172 which underlies the flange150 and extends between the plug 160 and the spherical head 168. Aspring retainer 174 is carried by the lower part of the shank 164 andrests upon the spherical head 168.

In order to assure the complete closing of a valve, it is necessary thatthere be provided a slight play in the valve train to compensate forelongation due to temperature changes. On the other hand, there shouldnot be too much play in the valve train, inasmuch as this would permitbattering of those parts between which there is relative movement. Bypermitting the upper end of the shank 164 to strike the stop member 156so as to act as the tappet of the valve train, the desired adjustment ofthe valve train may be obtained by adjusting the position of the stopmember 156 with respect to the upper end of the shank 164. 7

At this time it is pointed out that the adjustable connection betweenthe rocker arm and the push rod will not be limited to the springarrangement of Figure 6, but may be used in conjunction with the rockerarm 42 and the spring arrangement of Figure 1.

The foregoing is considered as illustrative only of the principles ofthe invention. Further, since numerous modifications and changes willreadily occur to those skilled inthe art, it is not desired to limit theinvention to the exact construction and operation shown and described,and accordingly all suitable modifications and equivalents may beresorted to falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. A valve train assembly for internal combustion engines comprising arocker arm shaft, a rocker arm mounted on said rocker arm shaft, firstmeans on the underside of said rocker arm at one end thereof forengaging a push rod, second means on the underside of closing position,said second means including a universal joint whereby a valve connectedto said rocker arm is free to rotate while being positively actuated bysaid rocker arm.

2. A valve train assembly for internal combustion engines comprising arocker arm shaft, a rocker arm mounted on said rocker arm shaft, firstmeans on the underside of said rocker arm at one end thereof forengaging a push rod, second means on the underside of said rocker arm atthe opposite end thereof for positive connection to a valve, said secondmeans including a ball member having an attaching rod and a socketmember having an attaching rod, said ball member being seated in saidsocket member with said attaching rods extending generally in oppositedirections.

3. A valve train assembly for internal combustion engines comprising arocker arm shaft, a rocker arm mounted on said rocker arm shaft, firstmeans on the underside of said rocker arm at one end thereof forengaging a push rod, second means on the underside of said rocker arm atthe opposite end thereof for positive connection to a valve, said secondmeans including a ball member having an attaching rod and a socketmember having an attaching rod, said ball member being seated in saidsocket member with said attaching rods extending generally in oppositedirections, said socket member including a plurality of ball elementsengaging said ball member.

4. A valve train assembly for internal combustion engines comprising arocker arm shaft, a rocker arm mounted on said rocker arm shaft, firstmeans on the underside of said rocker arm at one end thereof forengaging a push rod, second means on the underside of said rocker arm atthe opposite end thereof for positive connection to a valve, and springmeans engaged with said rocker arm for urging said rocker arm to a valveclosing position, said second means including a ball member having anattaching rod and a socket member having an attaching rod, said ballmember being seated in said socket member with said attaching rodsextending generally in opposite directions.

References Cited in the file of this patent UNITED SEATES PATENTS2,015,135 Brady Sept. 24, 1935 FOREIGN PATENTS 303,287 Italy Nov. 26,1932 600,309 Germany July 19, 1934

